News
Microsoft Opens Teams Phone to Custom Call Workflows
Microsoft is expanding the capabilities of Teams Phone with a new extensibility preview that allows organizations to build and integrate custom call workflows using Azure Communication Services (ACS).
The public preview, announced last week, enables developers to customize how inbound and outbound calls behave in Teams Phone. Through new APIs, developers can reroute calls, add intelligent routing decisions, inject pre-call or in-call workflows and integrate external systems for scenarios such as contact centers, virtual receptionists or compliance call recording.
According to Microsoft, the extensibility is made possible through ACS's server-side calling APIs, which allow applications to act as intermediaries in Teams call flows. The company said that this preview looks to build on previous efforts to connect Teams with Azure's communications infrastructure to expand options for organizations that require tailored call handling logic.
Developers can now create apps that connect directly to the Teams Phone system and receive webhooks for call events. From there, they can choose what happens next with the call -- whether to send it somewhere else, record it, add useful data, or connect it to a live agent. The API lets them accept or reject calls, transfer them, or start other actions based on their business rules.
Microsoft said the new features are suited for organizations that rely on advanced telephony use cases. Scenarios include PCI-compliant payment flows, identity verification before connecting a call, and call routing informed by CRM or service desk data. Importantly, these integrations remain within the Microsoft 365 ecosystem, allowing for consistent identity and security management through Entra ID.
The preview is currently available in select regions, with Microsoft planning to expand it to more locations in the near future. Right now, the focus is on Teams Phone setups connected to the public phone network (PSTN), but future updates could include support for direct or internal Teams calls as well, according to the company. Microsoft also said it will be taking feedback on the preview in developing future updates.
This update is part of Microsoft's larger effort to make Teams more customizable for developers. At Microsoft Build 2025 in May, the company introduced new tools across Teams, Copilot and Azure, reinforcing its goal to bring communications, productivity and AI together under one unified platform.